A New Ultrasonic Assisted Cloud Point Extraction and Preconcentration Procedure for the Spectrophotometric Oxalate Determination in Beverages

Anew ultrasonic-assisted cloud point extraction procedure (UA-CPE) was developed for preconcentration of oxalate in beverages prior to determination via spectrophotometry. At optimal conditions, the calibration curve was highly linear in a working range of 0.4–170 µg L? 1. The limits of detection and quantification were 0.12 and 0.40 µg L? 1. the precision as the percentage relative standard deviation, RSD% (n: 5; 10, 15, 30 µg L? 1) was lower than 3.5%. The method was successfully applied to the determination of soluble and total oxalate in beverage samples using two different acidic extraction approaches under ultrasonic power. Finally, the method was validated by comparing the results obtained with those of the reference method.